diff options
authorPaul Mackerras <paulus@samba.org>2005-11-19 21:24:55 +1100
committerPaul Mackerras <paulus@samba.org>2005-11-19 21:24:55 +1100
commit54c4e6b5fee0347ab81e2c2fe4239c455c3422ae (patch)
parent0212ddd839470f7a54cccccbaecd4833b4123da2 (diff)
powerpc: Fix bug in timebase synchronization on 32-bit SMP powermac
We were using udelay in the loop on the primary cpu waiting for the secondary cpu to take the timebase value. Unfortunately now that udelay uses the timebase, and the timebase is stopped at this point, the udelay never terminated. This fixes it by not using udelay, and increases the number of loops before we time out to compensate. Signed-off-by: Paul Mackerras <paulus@samba.org>
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/powerpc/platforms/powermac/smp.c b/arch/powerpc/platforms/powermac/smp.c
index 957b0910342..fb2a7c798e8 100644
--- a/arch/powerpc/platforms/powermac/smp.c
+++ b/arch/powerpc/platforms/powermac/smp.c
@@ -34,6 +34,7 @@
#include <linux/errno.h>
#include <linux/hardirq.h>
#include <linux/cpu.h>
+#include <linux/compiler.h>
#include <asm/ptrace.h>
#include <asm/atomic.h>
@@ -631,8 +632,9 @@ void smp_core99_give_timebase(void)
/* wait for the secondary to have taken it */
- for (t = 100000; t > 0 && sec_tb_reset; --t)
- udelay(10);
+ /* note: can't use udelay here, since it needs the timebase running */
+ for (t = 10000000; t > 0 && sec_tb_reset; --t)
+ barrier();
if (sec_tb_reset)
/* XXX BUG_ON here? */
printk(KERN_WARNING "Timeout waiting sync(2) on second CPU\n");